Ice making



Oct. 10, 1950 M. G. LEESON 2,524,815

ICE MAKING Filed Jan. 22, 1945 7 Sheets-Sheet 1 "/INVENTOR erald Leeson M. G. LEESON Oct. 10, 1950 ICE MAKING '7 Sheets-Sheet 2 FiledJan. 22, 1945 M 55mm 11%;?

Oct. 10, 1950 M. G. LEESON 2,524,815

ICE MAKING Filed Jan. 22, 1945 7 Sheets-Sheet 3 INVENTOR M. erald' Leesorz 41%: M f M WLS ATTORN YS Oct. 10, 1950 M. e. LEESON 2,52

ICE MAKING Filed Jan. 22, 1945 7 Sheets-Sheet 4 /06 Pr s ure L20 Cutout Pump Ice Breaker Water Valve Makeup Compressor INVENTOR M. geralcl Leeson M. G. LEESON Oct. 10, 1950 ICE MAKING 7 Sheets-Sheet 5 I r I I I;

ltllij n M w s e e ml Mm d T M w/ M Oct. 10, 1950 M. G. LEESON 2,524,815

ICEVMAKING Filed Jan. 22, 1945 7 SheetsS heet 6 N V J O CQ= INVENTOR M eralcl Leeson' ATTOR EYS Oct. 10, 1950 M. s. LEESON 2,524,315-

ICE MAKING Filed Jan. 22, 1945 '7 Sheets-Sheet 7 $1 l IQ)! 25 T INVENTOR 4 M. erald Leeson ATTO Patented Oct. 10, 1950 ICE MAKING Meldon Gerald Leeson, York, Pa., assignor to Flakice Corporation, Brooklyn, N. Y., a corporation of Delaware Application January 22, 1945, Serial No. 573,939

17 Glaims.

This invention relates to refrigeration, and more particularly to making clear ice in the form of cubes or other small pieces of regular shape.

An object of this invention is to provide a method and apparatus for making ice in an efficient and dependable manner. A further object is to provide for the making of clear pieces or cubes of ice in the form in which the ice is to be used. A further object is to provide apparatus of the above nature which is sturdy and practical in construction and which is efficient and dependable in use. These and other objects will be in part obvious and in part pointed out below.

The invention accordingly consists in the novel steps and combinations thereof and the features of construction, combinations of elements and arrangement of parts as will be exemplified in the structure to be hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the drawings:

Figure 1 is a partially schematic perspective view of one embodiment of the invention with the casing represented in broken lines;

Figure 2 is a front elevation with the casing broken away of an embodiment of the invention which is different from that of Figure 1;

Figures 3 and 4 are left and right side elevations of the embodiment of Figure 2;

Figure 5 is a top plan view of the embodiment of Figure 2;

Figure 6 is a schematic electrical circuit of the embodiments of Figures 1 and 2 to 5;

Figure 7 is a vertical section with parts broken away showing the details of the ice freezing and breaking unit of the embodiments of Figures 1 and 2 to 5;

Figure 8 is a front elevation of the ice-freezing unit of Figure '7;

Figure 9 is a left-side elevation from the lefthand side of Figure 8;

Figure 10 is a partially schematic view of portions of another embodiment of the invention; and,

Figure 11 is a view similar to Figure 8 showing the ice-freezing unit of Figure 10.

In accordance with the present invention clear ice is made in the form of cubes it being understood that the term cubes designates small pieces of ice of uniform size and shape whether or not they respond to the geometrical definition of this term. The term "clear ice is used to identify hard and solid ice which is relatively transparent, and to distinguish such ice from white ice which may be hard or soft and spongy. In accordance with the present embodiments of the invention, ice is frozen in the form of long tubes which are square in cross-section on the outside with a cylindrical hole through the center. These tubes of ice are broken or severed into lengths to form the ice cubes.

In the embodiment of Figures 2 to 5 some of the structure differs from that of Figure 1. However, the operation is similar, and in some respects it may be considered that the showing of Figure 1 is a simplified and partially schematic representation of the embodiment of Figures 2 to 5. For purposes of convenience the apparatus and its operation are explained in connection with Figure 1, and the respective parts in the other figures are given reference characters corresponding to those in Figure 1; the operation of the apparatus shown in the other figures is similar to that described in connection with Figure 1 except where a different operation is obvious or where a different operation is explained.

Referring particularly to Figure 1 of the drawings, a casing 2 is represented in broken lines and has a lower compartment 4 divided by a heat-insulatin partition 6 from a cold upper compartment 8. The lower compartment 4 encloses at the right a compressor I0, and an electric motor [2 which drives the compressor through a pair of pulleys and a V-belt l4. At the left of compressor Ill is a water pump [6 and its driving motor I8; and toward the front of the compartment is a water tube condenserreceiver 20 which condenses the refrigerant compressed by compressor IB and also provides for the storage of the condensed refrigerant before the refrigerant passes to the evaporator. Beneath the condenser-receiver is a water storage tank 22, the function of which will be explained below, and at the extreme left of the compartment is an electric motor 24 which drives a gear 26 through a speed-reduction gear assembly 28. Gear 26 carries a drive chain 31 through which motor 24 drives breaker rollers to break the ice in a manner explained below.

The upper compartment 8 encloses a freezing unit 30 which is shown in section in Figure 7 and in elevation in Figures 8 and 9. Freezing unit 30 includes a set of vertical freezing pipes 42 which are covered by insulation and enclosed in a rectangular shell 29 (Figure '7); the water to be frozen flows down the inside of the freezing pipes and ice of tubular shape is formed therein which is then melted or harvested by warming the freezing pipes. Directly beneath the freezing pipes are two breaker rollers 32 and 34 each of which is provided with six spiral ice cutters 35 (see Figure 1). Breaker rollers 32 and 34 are geared together by a pair of mating gears 3| and 33 and are driven through a gear 2'! keyed to the shaft or roller 32. Gear 21 is driven through chain 31 from gear 25 and motor 24 as referred to above. During the harvesting operation the breaker rollers are rotated as indicated so that their adjacent peripheries move downwardly together, and they cooperate to break the tubes of ice into predetermined lengths to form cubes.

Beneath the breaker rollers is a sump tank 36 which holds the main body of water to be frozen; during the freezing operation some of the water which is delivered to the freezing pipes passes through them without being frozen and flows from the bottom of the pipes between the breaker rollers and down into the sump tank again. Positioned over the top of the sump tank and slanting downwardly from behind the breaker rollers toward the front of the compartment is a screen 38 through which the water flows from the bottom of the freezing pipes into the sump tank, but this screen deflects the ice cubes toward the front of the machine as the cubes are discharged from the breaker rollers. At the lower edge of screen 38 is an ice storage drawer 39 for the storage of the ice cubes. Drawer 39 is slidable and may be pulled out when desired for the removal of ice. At the top of compartment 8 and resting on shell 29 is a water distributing tank 40 which receives the water to be frozen through a distributor pipe 4| and which directs the water into the various freezing tubes.

The structure of the ice-freezing unit is best shown in Figures 8 and 9 there being a bank of vertical pipes 42 which are square in cross-section and which are positioned in side-by-side parallel relationship with their contacting sides braised together. Positioned respectively on the opposite sides of the bank of pipes are two evaporator coils 44 which are attached at their upper ends to a gas-outlet header 46 and which receive liquid refrigerant at their lower ends through connections 48. Extending parallel to and contacting each coil 44 is a water tube 50 through which water flows during the harvesting operation to melt and free the ice from the freezing pipes 42. Each of coils 44 and its adjacent water tube 50 are braised together and to the side of the bank of freezing pipes so that heat is readily conducted from and to the freezing pipes.

Referring again to Figure 7, distributor tank 40 has formed in its bottom wall a plurality of protruding pockets 52 which act as water distributing heads with one pocket projecting into the top of each of the freezing pipes 42. Each pocket has four holes 54 positioned respectively opposite the centers of the four sides of its freezing pipe. Thus, the water flows from tank 40 through holes 54 and is directed against the four side walls of each pipe with the result that an even sheet of water completely covers the inner pipe walls. Meanwhile refrigerant is supplied to coils 44 with the result that the freezing pipes are cooled and a thin layer of ice starts to build up on the inner walls of the pipes. The rate of flow of the sheet of water is sufficient to make the ice clear as it is formed, and as the layer of ice in each freezing pipe becomes thicker, the central opening through the ice tube becomes smaller and approaches a circle in cross section. Thus, tubes of clear ice are formed of uniform high quality. The water in excess of that which is frozen flows from the bottom of the freezing pipes between the breaker rollers 32 and 3 and through screen 38 into sump tank 33. From here the water is recirculated in a manner to be more fully described below.

After ice of sufficient thickness has been frozen in pipes 42 the refrigerating process is discontinued and the freezing pipes are warmed to harvest, or melt the ice tubes free. This warming of the pipes is accomplished by flowing water through water tubes 50 and as each ice tube is released it slides down its freezing pipe until the lower end of the ice tube moves against a pair of the ice cutters 35 on the breaker rollers 32 and 34. As pointed out above, the breaker rollers are geared together and the ice cutters 35 are positioned in mating relationship so that beneath each ice tube is a pair of the ice cutters moving down opposite each other. Thus, the free fall of the ice tube is stopped but the ice tube continues to move resting on the two ice cutters. Continued rotation of the breaker rollers brings the next pair of ice cutters into engagement with the opposite sides of the ice tube, and the wedge shaped edges of the ice cutters enter the ice tube and sever the lower end therefrom to form an ice cube. Thus, the breaker rollers measure off and sever the ice tubes into predetermined lengths, and the spiral arrangement of the ice cutters results in the tubes being severed successively one after another; that is, a pair of the ice cutters engages the ice tube at one end of the bank of freezing pipes first and then engages the other ice tube successively down the bank. This gives uniform load on the motor. The ice cubes are discharged by the breaker rollers and fall onto screen 38 which directs them to the right into the top of the ice storage drawer 39. The rotation of the breaker rollers is started at the time that the harvesting operation is started and continues until all of the tubes have been severed into cubes.

Referring again to Figure 1, the gas refrigerant from header 46- is withdrawn through a U- pipe 58 to a heat exchanger 60 where it passes into heat-exchange relation with the liquid refrigerant and thence through a pipe 62 to compressor ID. The compressed refrigerant from compressor l0 passes through a pipe 64 to the condenser-receiver 20 where it is condensed, and the liquid refrigerant is stored. The liquid refrigerant is withdrawn from condenser-receiver 20 through a liquid tube 66 which passes through heat exchanger 60 to a control and expansion valve 68. Valve 68 is a conventional expansion valve with a thermal element including a tube 10 and a bulb 12 in heat-exchange relationship with U-pipe 58. This thermal element maintains constant superheat in the suction gas. During the harvesting cycle, compreszor If) is stopped so that there is no longer any cooling of the freezing pipes.

When the apparatus is in operation, water is pumped from the bottom of tank 36 through a pipe 14 by pump l6 and thence upwardly through a pipe 16 to a three-way valve 18. During the freezing portion of the cycle, the water from valve 18 flows through pipe 4| at two points into distributor tank 40. During the harvesting operation, the water from valve 18 flows through Water tubes 50 to Warm the freezing pipes and melt the ice free. Accordingly, valve 18 is provided with a solenoid 82 which is energized during the harvesting operation to raise the valve 5.. element of valve 18 and thus close the opening to pipe M and open the openings to pipes 56.

The make-up water, which is added to the water in tank 36 to replace the water frozen, is drawn from the water storage tank 22. The supply pipe is indicated in broken lines at 84 and has its outlet controlled by a float valve 86 having a float 81 which rises and closes valve 86 when the water in the sump tank reaches a predetermined level. However, make-up water is added only at the beginning of the harvesting cycle, and accordingly, a solenoid valve 88 is provided in pipe 84 which is maintained closed during the freezing operation, but which is opened during the harvesting operation by the energization of a control solenoid 89. At the beginning of each freezing operation the sump tank 36 is full to a predetermined level under the control of float 81, and as ice forms in the freezing pipes, the level of water in the sump tank falls slowly an amount corresponding to the volume of water frozen, and at the end of each freezing operation, float 81 has been lowered sufficiently to open valve 86. Then when the harvesting operation is started, solenoid 89 is energized and this opens valve 88 so that the water starts to flow into the sump tank from tank 22; when sufficient water has been added, float 81 is lifted and valve 86 is closed. At the end of the harvesting operation, solenoid 89 is deenergized and valve 88 closes, and during the freezing operation, no more water is added even though the water level falls.

It is desirable to provide for the efiicient use of the cooling water used to cool the refrigerant in the condenser-receiver 29, and in accordance with the present invention this is accomplished by restricting the flow of the water through the condenser-receiver with an outlet metering valve. This valve is opened as the temperature of the condenser-receiver rises so that a predetermined temperature is maintained in the condenser-receiver, and the water flowing from the condenserreceiver is heated to a predetermined temperature. As stated above, this water is stored in storage tank 22 and is used as feed water; thus, in addition to providing for the economical use of water in cooling the condenser, the arrangement also provides a source of constant-temperature feed water. Referring particularly to Figure 1, water is supplied to the condenser-receiver through a pipe 90 and flows to storage tank 22 through a pipe 92. The discharge from tank 22 is through a pipe 94 to which pipe 84 is attached. Pipe 94 is provided with a metering valve 96 which is spring actuated toward its closed position and is opened in response to a rise in pressure in the condenser-receiver. The control of valve 96 is obtained by providing a connection through a tube 98 from valve 96 to the compressed refrigerant line 64 which delivers the compressed refrigerant to the condenser-receiver. A rise in the temperature of the condenser-receiver causes a rise in back pressure in line 64, and this back pressure acts through tube 98 and is effective to open valve 96 and permit water to flow from storage tank 22. This in turn permits additional cool water to flow through the condenser-receiver with the result that the condenser-receiver temperature falls.

Storage tank 22 holds an amount of water which is in excess of that required as make-up water at any one time. Thus, at the beginning of each harvesting operation, feed-water at a controlled temperature is added to sump tank 36 and the amount of this feed-water is fairly constant because the amount of ice frozen during each freezing operation is fairly constant. Furthermore, the temperature of the water in tank 36 is practically the same at the end of each freezing operation, and due to all of these constant factors the temperature of the water in sump tank 36 after the feed-water has been added is substantially the same during each cycle of operations.

As pointed out above, the ice is harvested by pumping the water from tank 36 through pipes 50, and this thawing operation is started at the same time that the feed-water starts to flow into tank 36. At the start of the harvesting operation, the first water that flows through pipes 50 is at the temperature of the water last supplied to the freezing tubes, and as the warm feed-water mixes with the cold water in tank 36, the temperature of the water in the tank and thus of that flowing through pipes 58 rises. In this way the ice in the freezing pipes is not subjected to a sudden temperature change which might prove detrimental. The harvesting operation is carried on for a predetermined period of time, and by adding the feed-water at the beginning of the harvesting operation, the feed-water is precooled by the harvesting operation. This precooling is also a constant factor so that the temperature of the water in tank 36 is substantially the same at the beginning of each freezing operation. Distributor tank 40 is provided with an overflow pipe 99 which is connected to sump tank 36. Thus, when the water level rises in tank 40 above the level of pipe 99, the excess water is returned to the sump tank.

This apparatus is controlled by a timer mechanism so that the ice-making and harvesting operations are carried on in the proper timed sequence; the electrical control circuit is represented schematically in Figure 6. Power is supplied from any conventional electrical source, and the closing of the main switch I92 connecm the source leads I64 and I96 directly across the timer motor I68 and the water pump motor I8. The timer motor drives the timing unit I99 which has a follower arm III), a two-position cam H2, and a pair of contacts H4 and H6. When cam H2 is in the position shown, follower arm H9 is held in engagement with contact H4, and lead I94 is thus connected to a lead I I8 which extends through a low pressure cut-out switch I20 to one side of the compressor motor I2, the other side of which is connected to lead I96. When the cam has rotated so that follower arm H9 engages the low position on the cam, the follower arm engages contact II6'thus connecting lead I04 to a lead I22 which is connected to one side of ice-breaker motor 24, solenoid 82 of valve I8, and solenoid 89 of the make-up solenoid valve 88, The other side of each motor 24 and solenoids 82 and 89 is connected to lead I96.

Thus, during the ice-making portion of the cycle, follower arm III] is held in the upper position with the result that compressor motor I2, pump motor I8, and timer motor I08 are operated; cam H2 is turned at a constant rate, and the rate is such that the desired amount of ice has been frozen in pipes 42 at the time the low portion on the cam is presented to follower arm III]. This moves the'follower arm away from contact H4 and into engagement with contact II6 with the result that the compressor motor H2 is stopped, and the ice-breaker motor is started and solenoids 82 and 89 are energized. The energization of solenoid 82 moves the element of valve 18 to the upper position whereby the water is diverted from the freezing circuit and is directed through the Water pipes 50 so as to start the ice-melting r harvesting operation. The energizationof solenoid 89 opens the makeup water valve 88 and permits water to flow from storage tank 22 into tank 36. This flow is stopped by the raising of the float 8'! and the closing of valve 86 at the time water in tank 36 reaches a predetermined level. The water from the lower ends of water pipes 50 returns to tank 36, and the circulation continues until the end of the harvesting operation. The various tubes of ice may fall from the freezing pipes at different times, but the continuous operation of breaker rollers 32 and 34 insures the prompt severing of each tube into ice cubes.

At the end of the harvesting operation, cam II2 moves follower arm IIO back to the position shown, and the freezing operation is started again. Water tubes 50 are automatically vented by valve 18 so that the water drains from them immediately at the end of the harvesting operation. The timing unit I09 is provided with an automatic reset mechanism (not shown), whereby the shutting off of power moves cam II2 to the position which it occupies at the start of the harvesting operation. Thus, in the event of power failure, or if switch I02 is opened during the freezing operation for suflicient time to cause a partial melting of the ice, the freezing operation is not restarted immediately, but the freezing pipes are first cleared of any ice which they may contain.

With the present arrangement the feed-water temperature is fairly independent of the temperature of the water received from the water mains. Thus, regardless of variations in the water main temperature, the harvesting operation is completed during the time allotted for this operation. Furthermore, the preheating of the water in this manner insures ice of uniform high quality as well as of uniform shape and size. These are practical commercial considerations which are important in the art.

In the embodiment of the invention represented in part schematically in Figures 10 and 11, the elements not shown are the same as those of the other embodiments. Referring particularly to Figure 11, a bank of vertical pipes which are the same as freezing pipes 42 in the other embodiments includes alternate freezing pipes I24 and intermediate thawing pipes I26. The freezing pipes are used in the same manner in which pipes 42 are used and the thawing pipes I26 perform the function of water pipes 50 inthe other embodiments. Two evaporator coils I28 are positioned on the opposite sides of the bank of pipes with the runs of the evaporator coils extending vertically respectively along the various freezing pipes. The refrigerant coils are braised to the freezing pipes so that good heat conductivity is provided throughout the length of each freezing pipe. The liquid refrigerant enters the evaporator coils at the lower left-hand corner of Figure 11 and moves immediately up along the side of the first freezing pipe. At the top of the freezing unit the evaporator coil extends over to the next freezing pipe and thence downwardly. In this way each freezing pipe is subjected to the same cooling effect throughout its length with the result that ice is frozen in an even layer, and during harvesting, the ice is released with a minimum of melting. The water is directed down the freezing pipes only during the freezing operation and is directed down th thawing pipes only during the harvesting operation. Accordingly, a distributor tank I30 is mounted to slide longitudinally at the top of the bank of pipes. The tank is biased toward the position shown by a spring I32, and it is slid from this position by the energization of a solenoid I34. Four brackets (only two of which are shown) are mounted on the side of the freezing unit and each is provided with a pair of notches on which rest pins I38 fixed to tank I30. Thus, the tank tends to position itself accurately in one of its two positions. Tank I30 is provided with pockets for distributing water the same as is tank 40 except that the pockets are spaced further apart so that when the tank is in the position shown water is directed into the freezing pipes only, and during the harvesting operation, solenoid I34 is energized and water is directed into the thawing pipes only.

The refrigerant and water supply circuits and the control arrangement are all the same in the embodiment of Figures 10 and 11 as in the other embodiments. In the electrical circuit solenoid I34 is connected in the place of solenoid 82 of the other embodiments. Thus, distributor tank I30 is moved to the right during the harvesting operation and is held in the position shown during the freezing operation.

As many possible embodiments may be made of the mechanical features of the above invention and as the art herein described might be varied in various parts, all without departing from the scope of the invention, it is to be understood that all matter hereinabove set forth, or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

I claim:

1. In ice-making apparatus, the combination of, a cabinet structure having a heat-insulated upper compartment and a lower compartment, a refrigerator unit having an evaporator positioned in the upper compartment and having its other elements positioned in the lower compartment, means to supply cooling water to assist in condensing the refrigerant and to store a predetermined amount of water after the water has been heated by the condensing effect, water-discharge means to discharge water being stored when the condensing temperature reaches a predetermined value, water-supply means including a sump and water-pumping means to supply water from said sump to a freezing zone in heat-exchange relationship with said evaporator and alternatively to supply water from said sump to the vicinity of said freezing zone whereby ice formed in said freezin zone is harvested, and means to supply make-up water to said sump during the harvesting operation from the body of water stored.

2. In apparatus as described in claim 1 wherein the freezing zone is in a bank of vertical pipes which are square in cross-section and positioned in side-by-side relationship and said evaporator is formed by two evaporator coils positioned on the opposite sides of said bank of pipes, and wherein the water from the sump is supplied in even streams to the tops of said pipes by a distributor tank havin distributor pockets in the bottom thereof.

3. In apparatus as described in claim 1 which includes, a pair of breaker rollers positioned in parallel spaced relationship so that the ice is discharged between the rollers as it is harvested, and means to rotate the breaker rollers together whereby the ice is severed into cubes.

4. Apparatus as described in claim 1 wherein the water is distributed to the freezing zone by a distributor tank having distributor pockets in the bottom thereof, and means to position said tank alternately in two positions whereby water flows from the tank through the freezing zone during the freezing operation and water flows from the tank along thawing paths during the harvesting operation.

5. In ice-making apparatus, the combination of, a bank of vertical pipes which are substantially square in cross-section and which are positioned in parallel side-by-side relationship, means to refrigerate alternate pipes of said bank whereby water within said alternate pipes is formed into ice, and water-distributor means at the top of said pipes to supply water to be frozen to said alternate pipes during a freezing operation to form ice and to supply thawin water to the pipes other than said alternate pipes during a harvesting operation whereby the ice formed in said alternate pipes is melted free.

6. Apparatus as described in claim 5 wherein the water-distributor means comprising comprises an elongated distributor tank mounted for limited sliding movement at the top of said pipes whereby the tank directs the water down said alternate pipes when it is in one extreme position and directs water down the other pip-es when in the other extreme position, spring means bias-' ing said tank toward one extreme position, a solenoid assembly to move said tank to the other extreme position against the tension of said spring means, and a plurality of rigid brackets each having a pair of notches cooperatin with means on said tank to accurately direct the tank toward one of said extreme positions.

'7. In ice-making apparatus, the combination of, a bank of vertical pipes positioned in parallel side-by-side relationship and a pair of evaporator coils positioned respectively on the opposite sides of said bank of pipes with the runs of the coils positioned along the opposite sides of and parallel to alternate pipes of said bank.

8. In ice-making apparatus, the combination of, a bank of vertical freezing pipes positioned in parallel side-by-side relationship, a pair of evaporator coils positioned respectively on the opposite sides of said bank of pipes, and a pair of thawing-water pipes positioned respectively along and adjacent to said evaporator coils.

9. In the art of making ice, the steps of, pumping water to be frozen through a freezing zone, intermittently refrigerating said freezing zone to form ice therein and thereafter to permit the ice to be harvested, directing water adjacent said freezing zone during the harvestingoperation to melt the ice, adding make-up water during the harvesting operation, and preheating the makeup water to a predetermined temperature.

10. In the art of making ice, the steps of, recirculating water from a body through a freezing zone and alternatively along a, thawing path adjacent said freezing zone, refrigerating said freezing zone during an ice-making operation, preheating a body of make-up water during the freezing operation b heat of condensation of the refrigerant, and adding make-up water from the body of preheated make-up water at the start of the harvesting operation.

11. In ice-making apparatus, an evaporator and freezing tube assembly comprising a plurality of identical freezing tubes which are rigidly fixed together in vertical side-by-side relationship between two spaced parallel surfaces whereby each tube has two opposite side walls positioned respectively along said surfaces, an evaporator formed by two parallel evaporator sections each of which comprises a single pipe assembly composed of a plurality of substantially parallel horizontal runs connected respectively at their ends b connecting U-shaped portions with the two evaporator sections positioned respectively along said surfaces in heat-exchange relationship with the opposite sides of the freezing tubes and with the evaporator sections connected at their respective ends by refrigerant headers, and a water header resting on the top of said freezing tubes with its bottom wall substantially closing the upper ends of the tubes and with said bottom wall having formed therein a plurality of downwardly projecting integral distributor nipples which are positioned in the upper ends of the respective freezing tubes and which direct water from the water header against the inner walls of the freezing tubes in a downward direction.

12. In ice-making apparatus, the combination of, a freezin tube assembly comprising a plurality of vertical parallel freezing tubes of. substantially identical dimensions rigidly mounted with heat-conducting members therebetween and presenting two spaced parallel heat-transfer sur-, faces formed by the corresponding opposite sides of the respective freezing tubes, a refrigerant evaporator formed by two evaporator sections connected at their respective ends by refrigerant headers and comprising single pipe assemblies each having a pluralit of spaced parallel runs connected by U-shaped portions with the two evaporator sections positioned respectively on said heat-exchange surfaces in heat-exchange relationship with said freezing tubes, and means to circulate water through said freezing tubes comprising means constituting a water sump and a water pump and pipe assembly to withdraw water from the sump and direct itinto the top of said freezing tubes.

13. Apparatus as described in claim 12 which includes, a horizontally positioned ice-cutter assembly mounted at the lower ends of the freezing tubes which has a drive shaft extending along the side of the bottom openings of the tubes with means associated with the shaft which is projected against the ice as the ice falls from the tubes thereby to sever the ice int predetermined lengths.

14. Apparatus as described in claim 12 wherein the sump is positioned to receive water flowing from the bottom ends of the freezing tubes and ice-deflecting means extends over the top of the sump to direct ice from the bottoms of the tubes to the side of the sump, ice-cutting means positioned above the ice-deflecting means to sever the ice into predetermined lengths as it emerges from the bottom ends of the tubes, and heat-insulating means substantially covering said evaporator and said heat-transfer surfaces.

15. In ice-making apparatus, the combination of, a freezing tube assembly comprising a plurality of vertical parallel freezing tubes of substantially identical dimensions rigidly mounted in alignment between a pair of substantially parallel spaced surfaces whereby each tube has its two opposite sides positioned respectively along said surfaces, an evaporator formed by two evaporator sections adapted to be connected to operate in parallel in a refrigeration system and each comprising structure forming substantially continuous passageway which includes a plurality of spaced horizontal runs connected at their ends and positioned respectively in heat exchange relationship with the freezing tubes at said heat exchange surfaces, and means to circulate water through said freezing tubes comprising means constituting a water sump which is adapted to receive water from the bottoms of said tubes and a water tube and pipe assembly to Withdraw water from the sump and direct it into the top of said freezing tubes, said pipe assembly including a distributor at the top of the freezing tubes and having means for directing the water against the inner walls of the respective tubes.

16. Ice-making apparatus as described in claim 15 which includes, ice cutting means positioned beneath the tubes and adapted to cut the ice into pieces of predetermined size as it emerges from the bottom of the tubes, said ice cutting means comprising, a pair of breaker rollers rotatably mounted and spaced in parallel relationship and each having spiral ice cutter means mounted thereon and adapted to project into the ice as it passes between the rollers.

17. In ice-making apparatus, an evaporator and freezing tube assembly comprising, a plurality of substantially identical freezing tubes which are mounted in vertical relationship in alignment between two substantially parallel spaced surfaces whereby each tube has its two opposite sides positioned respectively along said surfaces, an evaporator formed by two parallel evaporator sections each of which is adapted to 12 receive refrigerant at the lower portion thereof and each of which is formed by means forming a continuous refrigerant passageway composed of a plurality of parallel horizontal runs connected respectively at their ends, said evaporator sections being positioned respectively along said surfaces in heat exchange relationship with said freezing tubes, and a water distributor at the top of said freezing tubes substantially closing the upper ends thereof and including means forming a water distributor at the upper end of each of the tubes which directs water substantially radially outwardly from the central portion of the upper end of each tube toward the walls thereof whereby the water flows downwardly along the tube walls in a rapidly moving even stream.

M. GERALD LEESON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 186,589 Lucas Jan. 23, 1877 2,032,404 Fisher Mar. 3, 1936 2,149,000 Udell Feb. 28, 1939 2,200,424 Kubaugh May 14, 1940 2,239,234 Kubaugh Apr. 22, 1941 2,319,523 Trigg May 18, 1943 2,387,899 Gruner Oct. 30, 1945 2,435,285 Lucia Feb. 3, 1948 

